Catalytic heater and system for preheating internal combustion engines by transmission and infrared radiation

ABSTRACT

A catalytic heater and control system is provided for efficiently preheating internal combustion engines in cold weather to facilitate starting. Heat is applied by transmission, by infrared radiation and by convection to the fluid contained within a heat-receptive housing (preferably the crankcase) of the engine. The heater comprises a shallow housing having a heattransmissive side which is affixed in contact with preferably the sump of the crankcase of the engine, which housing has a heatshielded forward shell or side and within which core defines a shell combustion chamber adjacent the attached conductive side of the casing. Within the combustion chamber is mounted a catalytic reactor extending longitudinally of the housing with an exposed substantial surface thereof facing rearwardly. Hydrocarbon fuel is obtained from the fuel source of the engine and, by control, is admitted intermittently in extremely small amounts to a conductive generating or vapor tube having vapor discharge orifice or discharge means disposed adjacent to the catalytic element. The system also includes an electrical heating coil for starting the heater or burner and which is preferably embedded in a pad upon which is superimposed the catalytic material, usually a pigment or sheeting carrying impregnated platinum or the like. The control system includes means for energizing the heating coil for only a short period for starting of the combustion operation and generation of the hydrocarbon gas or vapor.

UnitedStates Patent n91 Plender [45] June 25, 1974 CATALYTIC HEATER AND SYSTEM FOR PREHEATING INTERNAL COMBUSTION ENGINES BY TRANSMISSION AND INFRARED RADIATION [75] Inventor: Emil Pfender, West St. Paul, Minn.

[73] Assignee: Cordless Car Heater Co.', St. Paul,

Minn.

[22] Filed: Nov. 2, 1972 [21] Appl. No.: 303,281

[52] US. Cl.l23/142.5 R, 123/142.5 E, 123/179 H,

431/258, 431/268, 431/329 [51] Int. Cl. F02n 17/02, F23q 7/06, F23q 11/00 [58] Field of Search.. 123/142.5 R, 142.5 E, 179 H,

123/122 G;431/315, 17, 258, 323, 241, 329, 350, 268, 328, 344; 126/92 R, 92 RC, 92 B,

Primary Examiner-Charles .1. Myhre Assistant Examiner-Tony Argenbright Attorney, Agent, or Firm-Wil1iamson, Bains & Moore [57] ABSTRACT A catalytic heater and control system is provided for efficiently preheating internal combustion engines in cold weather to facilitate starting. Heat is applied by transmission, by infrared radiation and by convection to the fluid contained within a heat-receptive housing (Pre erab y. th crank ase; stilts; ng e The heater comprises a, shallow housing; having a heat transmissive side which is affixed in contact with preferably the sump of the crankcase of the engine, which housing has a heat-shielded forward shell or side and within which core defines a shell combustion chamber adjacent the attached conductive side of the casing. Within the combustion chamber is mounted a catalytic reactor extending longitudinally of the housing with an exposed substantial surface thereof facing rearwardly. Hydrocarbon fuel is obtained from the fuel source of the engine and, by control, is admitted intermittently in extremely small amounts to a conductive generating or vapor tube having vapor discharge orifice or discharge means disposed adjacent to the catalytic element. The system also includes an electrical heating coil for starting the heater or burner and which is preferably embedded in a pad upon which is superimposed the catalytic material, usually a pigment or sheeting carrying impregnated platinum or the like. The control system includes means for energizing the heating coil for only a short period for starting of the combustion operation and generation of the hydrocarbon gas or vapor.

11 Claims, 7 Drawing Figures PATENTEBJUR251974 8 8818.884

SHEET 1 BF 2 CATALYTIC IIEATER AND SYSTEM FOR PREHEATING INTERNAL COMBUSTION ENGINES BY TRANSMISSION AND INFRARED RADIATION BACKGROUND OF THE INVENTION The prior art discloses several different types of catalytic heaters for heating in coldweather, a reservoir or small tank connected with the radiator system of automotive engines. U.S. Pat. No. 2,737,169 is exemplary. Catalytic heaters have been used as space heaters and usually in a portable form for heating enclosures in tents and buildings. Typical examples of such heaters are shown in U. S. Pat. Nos. 3,240,256 and 3,457,021. At least two U. S. patents illustrated, in combinative use with catalytic reactors, the employment of an electrical heating element for starting purposes of the com bustion, to wit, U.- S. Pat. Nos. 3,199,505 and 3,291,199.

In contrast and distinction to said previously identified prior art, there has been no catalytic heater which employed and tapped into the hydrocarbon fuel system forthe engine and which in very short cycles periodically supplied and generated vapor and gas and directed the gas to a catalytic reactor, thereby producing with the construction and mounting of the small heater casing a lasting residual heat with transfer thereof to the lubricant in an automotive crankcase and with fur-,

thermore radiation of infrared rays directly to the casing. The-prior art catalytic heaters do not approximate the economy of the combinative structure of the inven- SUMMARY OF THE INVENTION This invention provides an efficient self-contained catalytic heater and control system for preheating internal combustion engines to facilitate starting thereof in the coldest weather and which system uses as its source of fuel to be catalytically ignited, the gasoline or other source of fuel of the engine itself. Through the employment of a rather large gas generating tube within the shallow combustion chamber the invention will essentially prevent any pollution of products of combustion since a new cracking of the often, leadcontaining gasoline takes place in the generating tube causing the lead in a cracking process to remain and adhere to the internal periphery of the tube. The construction of the shallow housing of the heater device with the hot side transmissi'vely attached to the sump or other portion of the crankcase, and with the opposite or outer side well shielded from transmission and radiation of the heat by intense combustion within the adjacent combustion chamber, releases casing and transmit heat to the lubricant itself, and which, through continuity of the oil system, will transfer heat throughout the working parts of the engine. The heat produced through transmission, convection, and by radiation of infrared rays to the lubricant heats the engine from the inside outwardly rather than in the case of heaters applied to tanks connected with the water-circulating radiator system. The small convective exhaust from the combustion chamber passes upwardly along the side of the crankcase and engine and is therefore of use as one of the several heating factors.

The novel catalytic heating device in general employs a compact shallow housing of small dimensions having a hot or rear housing side of good heat-conductive material which is in turn in contact with preferably the sump portion of the crankcase of the engine containing a large amount of the lubricating oil. The rear portion of the housing so attached constitutes a shallow com bustion chamber wherein is disposed an elongate gen erating tube with gas discharge means disposed in close relation to a catalytic pad or equivalent element occupying a substantial area of the internal cross sectional area of the combustion chamber. The tube is connected with the main fuel supply of the engine and in its flow system includes a small single-stroke pump which is controlled to operate in a rather rapid intermittent cycle (as short as 20 seconds, if desired) suddenly ejecting a very small quantity of the hydrocarbon fuel to the vaporizing tube;this action taking only a fraction of a second. Return of the pump ejector takes place in the remaining seconds of the cycle.

Included in the heater structure is an electrical starting coil which preferably is integrated with thepad or other support for the catalytic material and the energization of this electric coil is brought about by a single controlelement which has a timing means associated therewith for energizing the coil at the start of the operation of the device for only a short time and thereafter keeping the circuit to the coil open.

The burning of the gas generatedfuel in the combustion, rear chamber of the housing is sufficiently intense and continuous to produce infrared rays which,

single-stroke pump system for supplying fuel to the vaporizing or generating tube of the heater.

DETAILED SPECIFICATION In the accompanying drawings:

FIG. 1 is arear elevation with some portions broken away showing an efficient embodiment of the invention from a rear side elevation and with the heater detached from the crankcase to which it is, in operation, transmissively applied;

FIG. 2 is atop elevation of the heater detached with some portions of the housing broken away to show interior components;

FIG. 3 is a cross section taken substantially along the line 3-3 of FIG. 1.

FIG. 4 is a side elevation of a type of pump and pump housing for acting as the intermittent fuel injector;

FIG. 5 is a horizontal cross section of the pump of FIG. 4 showing valves, piston and inlet and outlet passages;

FIG. 6 is a schematic circuit diagram of the electrically operated intermittent fuel control means and includes circuitry for the electrical resistance coil employed for starting; and

FIG. 7 is a somewhat schematic sectional view showing an efficient tap device for branch connecting the small fuel system of the heater with the main fuel line of an internal combustion engine.

Referring now to the heater and burner construction of my invention, a shallow housing, indicated as an entirety by the letter H, comprises two metal sections S-1 and 8-2 inthe form of shells, the rearmostor hot shell S-l having substantially greater depth than the outer or forward shell S-2 and said shells having peripheral registering flanges F-l and F-2 which are suitably secured together by means, such as a number of spaced nutted bolts 10 which interconnect peripheral portions thereof. A sealing gasket 11 is interposed between the two shells S-1 and 5-2 as illustrated in FIG. 2.

The hot" shell 8-1 is constructed of metal having high heat conductivity and has a substantially flat heattransmissive side l2 defining with the peripheral side portions 12a and the flanges F-l, and with medially disposed divider partitions 13 and 14, a shallow combustion chamber C of substantial area. The interconnected shells S-1 and 8-2 and the overall heater housing formed thereby are secured in clamped relation to a heat-receptive portion of the engine, preferably to the sump forward portion of the crank housing. The securing of said assembled housing with the components thereof may be accomplished in any suitable manner such as by the elongate bolts 15 which have their threaded extensions screwed into tapped apertures formed in the appropriate portions of the front of the crank case or its sump, indicated by dotted lines as X in FIG. 2. In any event it is important that the planar surface 12 of the hot shell S-l be in contact flush with a substantial portion of the metal wall of the crank case or other heat-receptive portion of the engine.

The shell 5-2 of the housing is constructedfor shielding of the heat within the contents of the housing and to prevent radiation or loss of heat from that side. As shown Shell 5-2 is of multi-ply constructions, having an inner shell section 16 which on its inner face is zinc plated or of black metal to absorb heat. The next outermost shell ply 17 has its large inner surface coated for reflective purposes which may be accomplished with coating of tin. A third and outermost shell ply 18 is spaced from section 17 and preferably is of a metal or substance having poor heat-conductive characteristics.

I and for, in combination, nicely receiving and seating the oblong shaped pad unit P.

It will be understood that the overall heating housing H is positioned in upstanding or substantially vertical relation to a vertical surface on the crank case or crank case sump or other heat-receptive portion of the internal combustion engine.

The pad P has a body constructed of a very porous, inert, non-combustible material such as silicon or ceramic fibers or particles and is preferably molded to a rectangular size and shape to fit the two windows provided by the central divider partitions l3 and 14. The slightly outtumed flanges 13a and 14a embrace and retain the peripheral edges of pad P, An elongate tortuously formed resistance wire 20 is preferably embedded in pad P as shown in the drawings and the surface area of pad P facing towards the hot" side 12 of the heater is impregnated and smeared with a catalytic pigment now widely available on the American market, such as that descriptively known as black Magic containing minute particles of platinum. This impregnated surface is indicated as P-l in FIG. 2.

Referring again to resistance wire or coil 20, one end thereof is extended through the registering flanges and gaskets of the heater and as will hereafter be described, is electrically connected with a source of control supplied by current from the battery for the engine.

The other end may be groundedor attached in circuitry hereafter to be related.

An elongate gas-generating tube T constructed preferabiy of copper or other heat-conductible metal having also some affinity for lead, extends longitudinally through the combustion chamber C and is preferably somewhat flattened throughout its length disposed within said chamber with the said flattened portion opposed to and spaced from the impregnated surface P-l of the pad P (as shown in FIGS. 1 to 3 inclusive). The entering end of generating tube T passes through a sealed gasket T-l sealed in an apertured end portion in the larger housing section 5-1. The opposite end of the tube T is screw-connected and sealed with an elbow fitting 22 which passes through registering peripheral flanges of the divider partitions l3 and 14, (as shown in FIG. 2). Elbow 22 terminates in a discharge opening 22a which is disposed at one end of the shallow chamber identified as C-2 formed between the shielded shell 8-2 of the housing and the divider partitions l3 and 14 with the mounted pad P therein. The terminal 22a of the elbow has a threaded external clamping ring 23 which cooperates with a flanged portion 22b on the hot" side of the divider. If desired an angled deflection flange 23a may be provided for assisting in deflection of the generated gases and vapor into chamber C-2 although this is probably unnecessary since chamber C-2 is substantially sealed except for the porous pad P and actually in operation, a slight pressure above atomospheric is built up into chamber C-2. v

It will be noted (see FIG. 1) that generating tube T is declined somewhat from its entrance end to its juncture with the elbow fitting 22.

The intake end of the generating tube T outwardly of the gasket T-l is connected with a smaller diameter liquid fuel supply (21) line through the intermediary of a packing gland 21a.

For the necessary assistance for combustion of the catalyzed gases and vapors within combustion chamber C, upper and lower air louvers 24 and 25 are formed from the marginal stock at top and bottom of the hot casing shell or section S-l, thus providing elongate narrow openings at top and bottom of the heater casing which through gravity cause air during operation of the heater, to rise upwardly through the combustion chamber and with the upward flow of air from louver 24, impinging'against the forward crankcase of the engine To predeterminately control rapid intermittent injections of fuel throughthe supply line 21 into the intake of generating tube T, a solenoid (or relay) controlled single stroke pump Z, the structure of which is schematically illustrated in FIGS. 4 and 5 of the drawings. As shown the main pump housing Z has a spaced top plate 26 and an elongate base plate 27. For compactness and utility it is convenient to mount circuitry and components of the control system below the top plate 26 and upon the extension of the base plate 27 in some instances, but this mounting is not shown in the drawings since it is not thought to have pertinency to patent ability of the heater or heater system'Within the pump housing a small cylinder 28 is formed having slidably mounted therein a reciprocating piston 29 which is sealed with said cylinder by a pair of O-rings 29a. The piston is reciprocated by the armature or bar 30 of an electric solenoid having the usual encircling electromagnetic coil 30a. Energization of the coil 30a retracts the piston a short distance and compresses a strong actuating spring 31 and latches the armature arm and piston for subsequent electrically controlled release in predetermined short intervals. Connected. with the outer end portion of the smooth cylinder 28 and extending through one of the walls of the housing is a fluid intake passage and fitting 32 which communicates with the smaller fuel branch supply, and a ball check valve 34 controls intake of fuel in the retraction of the piston and closes off discharge during protraction of the piston. A small fu'el discharge passage and fitting 33 communicates through another wall of the pump housing Z with the fuel supply line 21 connected with the intake of the generator tube T. A ball check valve 35 with properly positioned ball seat in the passage, pro.- vides for ejection of a small quantity of fuel when the piston is protracted andcloses off communication with the discharge passage in the suction stroke of the pistOn. i

An important object of my invention is to simplify and compact all part of the heater and its control system, and to thus lower cost of manufacture and installation charges when my heater system is installed upon a vehicle such as a motorcar, snowmobile, snowplow or the like. Installation of prior art catalytic heaters has been costly because of complexity of tank heating and installation of usually a separate source of combustion fuel. As a part of applicant's general heater system combination i prefer the employment of a quick action tapping and connection-forming device for supporting the branch pipe through the generating tube and the small conduit for connecting with the main fuel line of the engine. A suitable embodiment of said tapping and connection device is illustrated diagrammatically in FIG. 7 of the drawings. in this structure two rigid coopcrating clamping members 40 and 41 are employed, clamped together upon an intermediate portion of the main fuel pipe 42 by suitable means such as the clamping screws 43. Members 40 and 41 form a seal about the clamped section of the main gasoline conduit and between the two provide a communicating chamber 44 whichhas a passage and threaded outlet 45 for connection of thesrnaller branch conduit for supplying fuel to my heater. The upperclamping member 40 is tapped vertically from the underside thereof to receive a sharply pointed externally threaded piercing head 46 which carries an axial upstanding stem 460 which at its upper extremity is notched or slotted for screwing engagement with a suitable screw-driver, Phillips wrench or the like. Axially communicating with the upper end of the tapped portion for receiving the piercing head 46, is formed a diminished aperture 47 for receiving the extremity of a screwdriver or the like. The shoulder formed by the upper extremity of the piercing head carries a sealing gasket 48.

in operation with the piercing head retracted the members 40 and 41 are clamped upon the main fuel conduit, and thereafter very quickly the piercing head is screw-protracted to pierce and thereafter withdrawn to a sealed position. Thus the branch passage 45 is interconnected with the interior of the main fuel line.

Referring now to HG. 6,.which shows the control circuitry associated with the catalytic heater invention, a conventional automobile battery a has its negative terminal grounded to the vehicle chassis and its positive terminal connected through conductor b to fuse 0. Conductor d extends fromfthe fuse to a main power switch e which is ordinarily mounted on the control panel of the vehicle. Conductors f and g extend from the switch to theinput of an electronic heater-timing circuit h. I M

The heater-timing circuit h is of a type well known to those skilledin the art and is arranged to turn on when an energy pulse is received along conductor g and to then remain on for a period of approximately 15 to 20 minutes. While the timing circuit h is on, it delivers an output signal along conductor 1' and through resistor j to the base of transistor 02, biasing the transistor to place it in an on" condition. After the 15 to 20 minute time period associated with the timing circuit h has expired, the circuit h turns off and :no longer provides a signal to actuate the transistor Q As the transistor turns on, current passes from the collector to the emitter of the transistor, flowing from the emitter terminal through resistor k and then to ground. This current flow from the emitter terminal of transistor 0, is adequate to provide a bias to the base of transistor 0 which is a power transistor, and places the transistor 0 in an on condition. As transistor Q3 becomes conducting, current can flow from conductor 1 through the transistor to ground. Because the transistor is intended to carry a heavy current adequate to energize the heater m, to which conductor 1 is connected. it is necessary that it be able to handle high current in the order of 15 amps. When the transistor switch is conducting, current is free to flow from the battery aalong conductor n to the heater m, energizing the heater, the current flowing thence along conductor 1, through transistor 0 to ground.

A conductor 0 extends from conductor f to an electronic repetitive switch circuit which is used to energize a solenoid s, as will be described hereafter. The switching circuit p is of a type known to the art and constructed so as to deliver an output pulse along conductor r and through resistor r to transistor 0 when the input terminal of the circuit p receives a pulse when the switch e is closed. The output pulse of the circuit p is of brief duration but adequate to turn on the transistor 0, by biasing the base thereof. As soon as the output pulse has been delivered from the circuit p, it immediately turns off and an internal timing circuit causes it to deliver additional pulses to the transistor Q1 at approximately second intervals so long as the switch e is closed. Accordingly, so long as the switch e is closed, the switching circuit p delivers repetitive output pulses along conductor r and through resistor t to the base of the transistor 01, turning the transistor 0. on at approximately 20 second intervals.

The switching circuit p also contains apparatus by which the frequency of the output pulse can be varied. Accordingly, by closing the switch e, the output pulses will be delivered to the transistor Q at approximately 2 second intervals, causing the transistor Q to turn on for a brief duration at 2 second intervalsv While specific time intervals have been referred to in conjunction with the switching circuit p and the timing circuit h, it should be understood that these time intervals can be varied somewhat without affecting the efficient operation of the invention, and such variation is within the purview of the invention.

Each time an output pulse from the circuit p is delivered to the base of transistor Q the transistor 0, becomes conducting and current flows from conductor d along conductor w, passing through the coils of solenoid s, to conductor x and then flowing through the transistor 0, to ground. Current flow through the solenoid s energizes the solenoid, causing the armature y to be moved to a cocked position, simultaneously compressing a spring 2 mounted coaxially about the pump shaft which is coupled to the armature shaft y. When the solenoid is de-energized, the spring z returns the shaft to its starting position. Cocking the armature shaft y creates a partial vacuum in the pump which draws liquid fuel into the pump. When the spring z returns the shaft to starting position, this forces the fuel into the combustion chamber. Because the output signal from the switching circuit p is of relatively short duration, the transistor O, is on for only a short period causing the solenoid s to be energized for only that short period. Energizing the solenoid s causes the armature y to be moved to a cocked position, simultaneously compressing a spring 1 mounted coaxially about the shaft of the solenoid armature. Accordingly, when the solenoid is de-energized as the output pulse of circuit p terminates. the compressed spring 2 swings the armature shaft to its original position.

Because the armature shaft is coupled to the shaft of a pump, movement of the shaft by the solenoid actuates the pump. When the solenoid is energized, the armature shaft moves to a cocked position which in turn causes a partial vacuum to be created in the pump to draw liquid fuel into the pump chamber. As the solenoid is de-energized, the compressed spring returns the shaft to original position causing the liquid fuel in the pump chamber to be ejected and transmitted to the combustion chamber.

In operation, when the heater is to be used, and operator closes switch e and current flows from the battery a along conductors 12 through fuse c, conductors d, switch e, conductor f and g to the heater-timing circuit h, turning the timing circuit on. When the circuit h turns on, it delivers an output signal to the base of Q turning the transistor 0 on. Current flow through Q in turn turns on transistor 0 which, becoming conducting, is in effect a closed switch. Accordingly, current flows from the battery a along conductor n through heater m and conductor 1 through transistor O3 to ground. This current flow through heater m causes the heater to become extremely hot, raising the combustion chamber to a predetermined temperature level. The heater-timing circuit continues in uninterrupted operation for approximately 15 to 20 minutes at the end of which the timer turns off entirely until it is reenergized by a new pulse delivered from the battery a by closing the main power switch e. The 15 to 20 minutes of continuous operation is adequate to cause the heater m to raise the combustion chamber to the desired temperature.

As soon as the main power switch e is closed, current also flows from the battery a along conductors b, fuse c, conductors d, switch e and conductors f and o to the input u of the electronic repetitive switching circuit p associated with the pump. Although the combustion chamber is not yet at the desired temperature to utilize incoming fuel, the switching circuit u goes into immediate operation as the switch 2 is closed, producing a series of output pulses delivered to the base of transistor 0, along conductor r at approximately 15 to 20 second intervals. Accordingly, the transistor Q, turns on at 15 to 20 second intervals for very short time periods. These time periods, however, are entirely adequate to energize the solenoid s to cock the armature shaft, and

compress the spring 2. As the solenoid s is de-energized by the circuit p, the spring z returns the shaft y to original position. The cocking of the shaft y serves to draw liquid fuel into the pump by creating a partial vacuum in the pump chamber. As the spring 1 returns the shaft to original position, the pump expels the liquid fuel into the combustion chamber, delivering it in a gaseous form.

Accordingly, once the switch e has been closed, the switching circuit p actuates the pump at approximately 15 to 20 second intervals during a time period of 15 to 20 minutes while the heater m is raising the combustion chamber to operating temperature. By the time that the operating temperature has been reached, sufficient fuel is present in the combustion chamber for normal operation. So long as the switch e is closed, the circuit p continues to actuate the pump at l5 to 20 second intervals to provide a steady stream of fuel to the combustion chamber to maintain a desired operating temperature for continued periods.

When it is desired to deliver a quantity of fuel to the combustionchamber over a relatively short period or alternatively to perform testing procedures on the apparatus, the operator may close switch v which causes the circuit p to deliver pulses to the transistor Q at approximately 2 second intervals. Accordingly, the combustion chamber can be filled with fuel by the pump in a much shorter interval when the switch v is closed.

OPERATION From the foregoing description the ease and economy of installation of my heater and its control system is thought apparent. The heater casing with the hot" side shell S-l is supported from attachment to the forward end of the pan or sump of the engine crankcase and clamping means such as the bolts 15 or other devices are employed with preferably strong spring tensioning means applied near the outer ends. The broad 9 hotarea surface l2 is thus transmissively applied to the exterior metal of the crankcase sump.

As previously stated branch fuel connection for the generating tube T of the heater is quickly made with minimal labor requirements by employing my tapping and connection device illustrated in FIG. 7. This operation also provides support of the upper end of the smaller branch line connected with the single-stroke pump device illustrated in FIGS. 4 and 5. Suitable supporting means such as an arm of bracket (not shown) is attached to the chassis of the engine-propelled vehicle, and such means supports the pump, the solenoid, and the pump housing. The top plate of the pump housing and the base thereof, as previously recited, have mounted thereon substantially all of the essential components and circuitry described in the explanation of the diagram of FIG. 6, so that the installer has no electrical connections to make or complete other than to install the starting switch e on the instrument panel and connect the electrical connections thereto including of course the line from the positive pole of the battery through thefusec to the line d and w.- y

The overall starting and continuous operation of the heater including starting-energization of the electric heating coil is accomplished by merely swinging the handle of the starting switch e. The control circuitry deenergizes theelectric heating coil 20 after generation of vapor fuel is accomplished in tube T. v

l have discovered that to provide substantial economy in the use of the hydrocarbon fuel and to assure continuity and elimination of fluctuation inthe burner operation, fast intermittent operation cycles of the solenoid-controlled pump is essential as well as construction or adjustment of the pump piston stroke 29 is necessary for the most desirable and economical results. My invention, in its preferred embodiments, employs a regulated intermittently or repetitive injection of an extremely small quantity of fuel into the generating tube T. The preferred stroke ejection of fuel ranges from one-third cubic centimeters to one-and-one-half cubic centimeters per stroke. The frequency intervals controlled by the electronic circuitry preferably range from one-fourth of a minute to one minute.

After discontinuance of the employment of the resistance heating element (usually 12 to 15 minutes after the switch e is thrown) sufficient gas and vapors have been generated in tube T and have penetrated the catalytic pad P and have been combusted in the chamber C for the overall operation of the heater and system. Gas and vapors forcibly discharged into the sealed shallow chamber 02 place said shielded chamber under a pressure above that of the combustion chamber, thereby rather uniformly causing the gases and vapor to traverse the full thickness of the porous pad P and in such passage the gas and vapors are catalyzed by the catalytic ingredients impregnated in the rearward surface of the pad and are combusted in the chamber C, further serving to continue generation of the hydrocarbon fuel passing through the tube T.

Through gravity and the intense heat produced in the combustion chamber, air from the bottom of the heater housing flows upwardly through the passage defined by louver and affords the necessary aid to combustion for the functioning of the burner structure. Air and products of combustion pass upwardly out of the heater casing through the slot defined by the upper louver 24.

With my heater structure as described and illustrated in the drawings an intense combustion continues steadily in the combustion chamber C and the high quantity infrared rays thus produced by radiation intensely heat the hot contact area 12 of the hot heater shell S-l, transmitting heat to the front of the crankcase sump and then by transfer, convection and radiation, quickly heat the large amount of lubricant in the pan or sump of the crankcase. Heating of this lubricant quickly causes circulation of the same in the crankcase and such circulation with its unity with the lubricant throughout the entire engine transfers and transmit this heat in relatively a short time to substantially all the working parts of the engine. Most internal combustion engines are so constructed that while no substantial circulation of lubricant takes place, when the engine is idle, provision is however made for a slight circulation of lubricant when the oil pump is not in operation. Such an auxiliary circulation, because of the high transfer of heat from my heater to the lubricant is very efficient in adequately heating the working parts of the engine, even in the coldest winter weather.

The aforesaid transfer of heat by transmission, radiation and convection is applied inwardly to the engine andits workingparts ratherthan externally as is the case in tank-heaters and known catalytic heaters of the prior art;

The heated air and small products of combustion directed upwardly through upper louver 24 of the heater, impingeagainst upper portions of the'crankcase and under portions of the engine forwardly thereof and assists in the overall, preheating operation.

By way of example i have found that in careful tests made of an embodiment similar to that illustrated in the drawings, and where the length of the interior of the heater housing is substantially 10 inches and the width approximately 4 inches, in employing controls for injecting in'each stroke of the fuel piston cubic centimeter of the usual gasoline or engine fuel, and controlling the frequency of operation to three cycles a minute I obtain results of production of B.T.U.s per square inch based on the area of the pad P, thus developing from 800 to approximately 1,000 B.T.Us. per hour. This has been found entirely adequate to very efficiently preheat even the larger internal combustion engines for starting in cold weather which reaches 40 below zero.

An important new result attained by the herein disclosed invention is the removal of lead from the usual gasolines and other hydrocarbon fuels supplied for intemal combustion engines. The hydrocarbon fuel entering intermittently in very small amounts in the enlarged copper tube generator T is actually cracked in this generation tube, thereby separating out the lead atoms and elements which alsmot entirely are collected upon the interior of tube T. Exhaustivetests and examinations of said tube T after the equivalent of 500 hours of operation of the heater has shown relatively heavy infestation of lead oxides and products on the interior of the tube with some infestation of leaded products on the interior of the heat-shielded shallow forwardchamber C-l. With removal of such lead the catalytic particles (usually platinum) of the pad are not affected by lead. This important new result, to the best of my knowledge, has not been accomplished by any of the prior art catalytic heaters.

In addition to the above recited new result the following important new and improved results and operation are accomplished by the use of my invention, to wit:

Heat intensively is transferred in the most direct and efficient manner (by conduction, radiation and transfer) to the large supply of fuel oil internally of the engine.

Utilization of the fuel source for the engine with great economy and efficient flameless combustion thereof is accomplished through the combination of cooperating elements of my heater and system with high frequency intermittent operation of fuel supply in extremely small quantities.

Flow of generated fuel gases over the catalytic agency is novel and efiicient.

What is claimed is:

l. A catalytic heater system for preheating internal combustion engines having in combination:

a heater housingdefming internally a combustion chamber and an adjacent fuel-vapor-receiving chamber, v I

said chambers being spaced apart through at'least partial areas thereof by the common medium of a porous partition composed of noncombustible material,

a generally tubular gas-generating medium mounted within said combustion chamber and having a discharge extended into and tenninating within said fuel-vapor-receiving chamber,

said generating medium having an intake connected with the liquid hydrocarbon fuel supply for said engine,

a catalytic surface unit disposed wholly within said combustion chamber in juxtaposition to said porous partition,

means for supplying very small quantities of said liquid fuel into said generating medium, the intensity of heat in said combustion chamber causing preliminary cracking of the hydrocarbon fuel passing therethrough.

2. The structure and combination set forth in claim 1 wherein,

said porous partition comprises a substantial part of the common wall between said combustion chamber and said fuel-vapor-receiving chamber and consists in an integral pad of inert, particulate material, and

said catalytic surface unit constituting a catalytic coating on the surface of said pad disposed in said combustion chamber.

3. The structure and combination as set forth in claim I further characterized by the said source of fuel supply for said engine containing lead compositions, and

said gas-generating medium comprising a high, heatconductive metal tube whereby in operation the intensity of heat in said combustion chamber produces a preliminary cracking of said hydrocarbon fuel to an extent to remove from the gaseous and vapored fuel therein a very large percentage of the lead contained in constituents of said fuel.

4. The structure and combination set forth in claim 1 wherein,

said porous partition constitutes a pad composed of inert noncombustible particulate material, said catalytic surface unit being coated on the surface of said pad disposed in said combustion chamber, and

an electrical resistance element embedded in said pad and having conductors for connections with an electrical circuit.

5. The structure and combination set forth in claim 1 wherein,

said porous partition and said catalytic surface unit are disposed vertically within said housing, and

air supply and venting means for said combustion chamber comprising exterior air communication means at the bottom of said combustion chamber and air and gas exhaust passages at the top of said combustion chamber disposed substantially in alignment with said bottom air communication means to cause travel of air as an aid to combustion in a path immediately adjacent the surface of said catalytic unit.

6. A catalytic heater system for preheating internal combustion engines to facilitate starting thereof having in combination;

a heater housing defining internally a combustion chamber,

means associated with said housing for transmitting heat produced therein to a heat-receptive portion of said engine,

a catalytic surface unit mounted within said combustion chamber for combusting hydrocarbon gases and vapors produced in said chamber,

a gas-generating device mounted in said combustion chamber and producing gas flow'toward said catalytic unit,

said generating device having an intake connected with the liquid hydrocarbon fuel supply for said en gine,

a fuel-injection device interposed in said intake connection and having a cycle of operation to inject in each cycle only a predetermined, very small amount of liquid fuel,

and control means for intermittently actuating said fuel-injection device in frequent, predetermined, spaced time intervals. v y

7. The structure and combination set forth in claim 6 wherein said fuel injector device comprises a single stroke injector element reciprocated by an electrical solenoid,

and means for periodically and very frequently energizing said solenoid.

8. The structure and combination set forth in claim 6, wherein said intennittently operable fuel injector device employs a small fluid displacement element and check-valve means constructed to measure and inject for each stroke, less than 2 cubic centimeters of liquid hydrocarbon fuel,

and control means operated at very frequent intervals within a range of from 20 to 50 seconds for actuating said piston.

9. The structure and combination set forth in claim 6 wherein an electrical solenoid unit is provided for actuation of said fuel-injection device, and

wherein an electronic means is provided for periodically energizing said solenoid unit at very frequent predetermined intervals.

10. The structure and combination set forth in claim 6 further characterized by a quick action tapping and connection-forming mechanism attachable readily to the main fuel line of said engine and having a retractable piercing element for initially penetrating the wall of said fuel line and having a surrounding independent 13 14 branch connection passage communicable with the fuel and a second adjacent and shallow, closed chamin said line after piercing and subsequent retraction of b 531d P said gas generating device having a gas and vapor disl condult means connecting Sad,passage the charge communicating with said last mentioned intake of said gas generating device. 5

11. The structure and combination set forth in claim ifi ifi and 3 3 bgfldmg z 6 further characterized by: sm POSl we pressure erein, w ere y genera e said catalytic unit having a body constructed of pogas f P thmugh l Porous Q rous, inert material, and being framed in apartition of said catalytic unit and enter said combustion mounting which medially divides the interior of 10 b said heater housing into said combustion chamber 

1. A catalytic heater system for preheating internal combustion engines having in combination: a heater housing defining internally a combustion chamber and an adjacent fuel-vapor-receiving chamber, said chambers being spaced apart through at least partial areas thereof by the common medium of a porous partition composed of noncombustible material, a generally tubular gas-generating medium mounted within said combustion chamber and having a discharge extended into and terminating within said fuel-vapor-receiving chamber, said generating medium having an intake connected with the liquid hydrocarbon fuel supply for said engine, a catalytic surface unit disposed wholly within said combustion chamber in juxtaposition to said porous partition, means for supplying very small quantities of said liquid fuel into said generating medium, the intensity of heat in said combustion chamber causing preliminary cracking of the hydrocarbon fuel passing therethrough.
 2. The structure and combination set forth in claim 1 wherein, said porous partition comprises a substantial part of the common wall between said combustion chamber and said fuel-vapor-receiving chamber and consists in an integral pad of inert, particulate material, and said catalytic surface unit constituting a catalytic coating on the surface of said pad disposed in said combustion chamber.
 3. The Structure and combination as set forth in claim 1 further characterized by the said source of fuel supply for said engine containing lead compositions, and said gas-generating medium comprising a high, heat-conductive metal tube whereby in operation the intensity of heat in said combustion chamber produces a preliminary cracking of said hydrocarbon fuel to an extent to remove from the gaseous and vapored fuel therein a very large percentage of the lead contained in constituents of said fuel.
 4. The structure and combination set forth in claim 1 wherein, said porous partition constitutes a pad composed of inert noncombustible particulate material, said catalytic surface unit being coated on the surface of said pad disposed in said combustion chamber, and an electrical resistance element embedded in said pad and having conductors for connections with an electrical circuit.
 5. The structure and combination set forth in claim 1 wherein, said porous partition and said catalytic surface unit are disposed vertically within said housing, and air supply and venting means for said combustion chamber comprising exterior air communication means at the bottom of said combustion chamber and air and gas exhaust passages at the top of said combustion chamber disposed substantially in alignment with said bottom air communication means to cause travel of air as an aid to combustion in a path immediately adjacent the surface of said catalytic unit.
 6. A catalytic heater system for preheating internal combustion engines to facilitate starting thereof having in combination; a heater housing defining internally a combustion chamber, means associated with said housing for transmitting heat produced therein to a heat-receptive portion of said engine, a catalytic surface unit mounted within said combustion chamber for combusting hydrocarbon gases and vapors produced in said chamber, a gas-generating device mounted in said combustion chamber and producing gas flow toward said catalytic unit, said generating device having an intake connected with the liquid hydrocarbon fuel supply for said engine, a fuel-injection device interposed in said intake connection and having a cycle of operation to inject in each cycle only a predetermined, very small amount of liquid fuel, and control means for intermittently actuating said fuel-injection device in frequent, predetermined, spaced time intervals.
 7. The structure and combination set forth in claim 6 wherein said fuel injector device comprises a single stroke injector element reciprocated by an electrical solenoid, and means for periodically and very frequently energizing said solenoid.
 8. The structure and combination set forth in claim 6, wherein said intermittently operable fuel injector device employs a small fluid displacement element and check-valve means constructed to measure and inject for each stroke, less than 2 cubic centimeters of liquid hydrocarbon fuel, and control means operated at very frequent intervals within a range of from 20 to 50 seconds for actuating said piston.
 9. The structure and combination set forth in claim 6 wherein an electrical solenoid unit is provided for actuation of said fuel-injection device, and wherein an electronic means is provided for periodically energizing said solenoid unit at very frequent predetermined intervals.
 10. The structure and combination set forth in claim 6 further characterized by a quick action tapping and connection-forming mechanism attachable readily to the main fuel line of said engine and having a retractable piercing element for initially penetrating the wall of said fuel line and having a surrounding independent branch connection passage communicable with the fuel in said line after piercing and subsequent retraction of said piercing element, and conduit means connecting said passage with the intake of said gas generating device.
 11. The structure and combination seT forth in claim 6, further characterized by: said catalytic unit having a body constructed of porous, inert material, and being framed in a partition mounting which medially divides the interior of said heater housing into said combustion chamber and a second adjacent and shallow, closed chamber, said gas generating device having a gas and vapor discharge communicating with said last mentioned closed chamber, and in operation building up a small positive pressure therein, whereby generated gas and vapors will pass through the porous body of said catalytic unit and enter said combustion chamber. 